I agree with the fuel pressure check. What a difference that makes in sound and smoothness. Since it is on hill's only I take it. What about a fuel pickup problem. I know my 99.5 superduty started two weeks ago dieing out of the blue. But it was clear that it was running out of fuel. They chug so hard it feels like the driveline is comming out. Well whats happening is it started running out of fuel at the 1/4 tank mark and buy refueling I know there is fuel in there. I wanted to do the pickup and return line mods anyway.